Meditation can focus the mind in a measurable way, according to a study of Buddhist monks. In a visual test designed to confuse the brain, the monks were able to stave off confusion more easily than those not trained in the contemplative arts.

Researchers studied 76 Tibetan Buddhist monks taking a test of 'perceptual rivalry', in which two conflicting images are presented, one to each eye. This usually causes the brain to switch back and forth between the images every few seconds as it struggles to make sense of what it is seeing.

Monks skilled in the art of 'one-point' meditation - which involves focusing all of one's attention on a single object or thought - were able to slow this switching down or even stop it completely, report Olivia Carter of the University of Queensland in St Lucia, Australia, and colleagues.

In their study, published online by Current Biology1, they asked monks with training ranging from to 5 to 54 years to practise different forms of meditation and then don a set of goggles which displayed two different images: horizontal bars to one eye, and vertical bars to the other.

“This is something that the average person cannot do.”

Olivia CarterUniversity of Queensland

The most experienced one-point meditators, who had spent more than 20 years in isolated retreats, were able to resist visual switching for the whole five minutes of the experiment. According to the monks' self-reported assessment, they saw only a single stable image with one set of bars dominant.

There was no noticeable improvement for monks who were practising 'compassion' meditation, which involves contemplating the suffering of others.

The monks were also given another test, of 'motion-induced blindness' (an example can be found at http://www.uq.edu.au/nuq/jack/bonneh.html), which involves staring at a stationary dot in the midst of a pattern of swirling dots, until the other stationary dots in the picture seem to disappear. Monks maintained this 'blindness' state for an average of 4.1 seconds, compared to just 2.6 seconds for ordinary people. The most experienced meditator managed to uphold the optical illusion for more than 12 minutes.

Streams of thought

The discovery supports that idea that meditation calms the mind and allows it to focus more clearly, says Carter. "Monks appear to be able to control the rate and content of thoughts flowing through their 'stream of consciousness'," she says.

Meditation could conceivably help people with depression, or who have recently suffered a trauma, to stop their minds constantly dwelling on negative thoughts, she suggests.

"It has long been claimed by practitioners of meditation that when faced with bad news or tragic events they are able to acknowledge the tragedy, but rather than dwell on the situation they have the capacity to redirect their thoughts to other, more positive directions," Carter says. "This is something that the average person cannot do."

But John Gruzelier, a neuroscientist at Imperial College London, warns that too much introspection and contemplation might be dangerous for someone struggling with depression.